Method of manufacturing rotors



" Sept. 15, 17925.

B W DAVID METHOD OF MANUFACTURING ROTRS Patented Sept. l5, 1925'.

UNITE-D STATES 1,553,511 PATENT orner.

BRUCE W. DAVID, 0F CLEVELAND HEIGHTS, 0R10, ASSIGNOR TO THE LINCGLN ELEC- TRIC COMPANY, 0l"A CLEVELAND,

OHIO, A CRPORATION 0F 01H10.

METHOD 0F FACTURING IRGTORS.

application and my a,

` To all whom it may concern:

Be it known that ll, BRUCE W. DAVID, a citizen of the United States and a resident of Cleveland Heights, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in, Methods of Manufacturing Rotors, ot which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other invent-ions. l

lin the armature windings of induction motors, such winding is placed in slots around the periphery of the laminated core ot the-armature. 1 Where, as in the so-called squirrel-cage type ot' winding, the latter cony sists simply ot a number ot heavy copper bars placed in suitable slots, these are formed into closed circuits by means ot connecting rings at the ends, which, inthe case of the armature, are known as rotor end rings. 'lhe satisfactory attachment of the ends of the bars to such end rings has always been a matter of considerable difficulty, inasmuch as such attachment has to be made after the bars are in place, and the full dll hill

cross-section of bars and ring must be pre- "ser'ved at all points it the current dow is not to -be impeded.

The object ot the present invention accordin'gly is the provision of an improved construction ot such end rings, and incildentally. thereto, an improved method ol attachingsame to the bars that constitute the winding whereby the difficulty in question may be overcome.

To the accomplishment ot the foregoing and. related ends, said invention, then, consists of the means and steps hereinafter' fully` described and particularly pointed out in the claims; the annexed drawing and the `lollowing description setting forth in detail certain means and one mode ot carrying out the invention, such disclosed means and mode illustrating, however, but one of various ways in which the principle of the invention may be used. v

lln said annexed drawing Fig. l is partly an axial section and partly a side elevation of an armature or rotor illustrating one form of my improved end ring construction;l llig. 2 is a sectional detail illustrating the method employed in constructing suchend ring or rather in at- 1921. Serial No. 482,044.

y'taching same to the bars constituting the winding; and Fig. v3 is asimilar view of a slightly modified orm ot construction.. ln both Figs. 1 and 3 the armature or rotor l is shown in diagrammatic outline only, the same being mounted on the usual shaft or spindle 2. ln the sectioned portion of these igures, there is shown one ot the bars 3, forming part ot the winding previously referred to, such bars `being held in suitable transverse slots, and having their ends, as best shown in Fig. 2, slightly projecting beyond the lateral edge of the rotor. In the specific form of construction shown in Figs. l and 2, these ends are homogenen ouslunited to a ring a of circular crosssection formed out ot a heavy wire or rod,

either case the external diameter ot the ring is such .as to permit it to' lit more-or less snugly just inside the projecting ends of the series of bars l3'. An annular retaining plate 5 or 5, as the. case maybe, is then pressed against the corresponding end ot the rotor, the outer portion of such plate being curved or bentto more or less closely conform with the corresponding ring. At the same time such plate, where the ring is ot circular cross-section, will be seen to form an encircling groove ortrough in which suchring lies, and over which the adjacent ends of: the'bars 3 project. Vllhe bars 3, as well as the ring Il, will ordinarily be of copper, although any conductor ot suitable resistance may be employed, while the annular plate 5 or 5 will preterably be ol a metal having a higher melting point and need not itself be a specially good conductor ot electricity. 'lhus ordinarily l make such plate f a melt rod 7, preferably of the same metal as the latter. .dsa result the spaces between lthe several bars, and between such bars and the ring are lilled up with molten metal from such rod, and at the same ti the surfaces ot the bars and ring are fused Sudiciently to cause them to be homogeneously united or welded into the mass of meta-l thus ldd ' deposited- It will be understood that penis of rectangular cross-section, the 'space in yus question is more completely lled, and the metal deposited from the pencil will lie wholly on the outer ace ofthe rin and between the ends of the rods 3. fter the welding `operation has been completed, the

, deposited metal, which may present something of an exerescence, as indicated in dotted outline in Fig. 1, may be turned off to present a smooth beveled surface, as indicated'l in full lines bothv in said ligure and in Fig. 3. i

The plate 5 or 5'lL will be suiciently firmly united to the end ring thus built up to securely hold such plate in place, and thus form of the same a permanent closure for the end of the rotor. While my invention has been particularly described with reference to the construction'of a rotor end ring it will be obvious that an end ring may be 'e built up in exactly the same way for use in other corresponding parts of an electrical machine, and no limitation is intended to be placed upon such use by such specific reference.

Other modes of applying the principle ofl my invention may be employed instead `of the one explained, change being made as regards the steps herein disclosed, provided those stated by any of the following claims or their equivalents be employed.f

I therefore particularly point out and distinctly claim as my invention 1. In the manufacture of rotors for induction motors and the like, the steps which consist in disposing a conductor ring adjacent the ends of the bars that constitute the winding of such rotor, holding said ring in place by means of an annular metallic plate pressed against the corresponding end of` said rotor, said plate havin a higher fusion point than said rings an bars, and then playing an arc fromL a suitable electrode over such ring and rod-ends whereby the latter are intertused and united to the adjacent portion of said plate. y

2. In the manufacture of rotors for induction motors and the like, the steps which consist in disposing a conductor ring adjacent Ithe ends of the bars that constitute the winding of such rotor, holding said ring in place'by means of an annular metallic plate pressed against the corresponding end of said rotorsaid plate having a higher fusion point than said rings and bars, playing an arc from a suitable electrode over such ring and rod-ends, and simultaneously melting a metal pencil in such arc, whereby such ringand rod-ends are interfused and united to the adjacent portion of said plate.

3. In the manufacture of rotors for induction motors and the like, the steps which consist in disposing a conductor ring adja' cent the ends of the bars that constitute the winding of such rotor, holding said ring in place by means ,of an annular metallic plate having its outer edge bent to form a trough in which such ring lies, the arms o the rotor said plate having a higher fusion point than said rings and bars, being maintained approximately horizontal, playing an are from a suitable electrode downwardly onto such ring, rod-ends and the adjacent portion of the plate-edge, and simultaneously melting a metal pencil in such arc, whereby such ring and rod-ends are interfused and united to such plate-edge.

Signed by me, this 24th da of June, 1921.

` BRUCE DAVID.

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